Embodiments of the present technique relate to a system and method for determining a flow condition and more particularly to determination and correction of the flow condition in wind turbines.
Wind turbines are increasingly being deployed as a renewable source of energy. One of the important aspects of wind turbine operation is to optimize wind turbine performance. Wind turbine optimization may be characterized by parameters such as aerodynamic efficiency, energy output, and noise, for example. Optimized operation of the wind turbine would lead to a reduced cost of energy and other benefits.
Modern wind turbines include very long blades experiencing large wind variations. Wind turbine blades designed for constant tip speeds, experience varying flow conditions due to varying wind dynamics and the presence of the earth's boundary layer. Impact of the wind variation across the blade may be reduced by employing local actuators that can vary the blade aerodynamics via flow control, blade pitch changes or changes to other operating parameters. This approach also reduces the wind induced loading on the rotor.
It is advantageous to detect local instantaneous blade flow state that can be used to provide information about effective inflow angle of attack which may further be used to apply local actuation to alter the aerodynamics of the blades and to improve the flow state. Flow separation of the boundary layer of the blade may generate stall. When stall occurs, lift generated by the blade reduces and also the torque imparted by the wind to the wind turbine is lost. Diminishing or delaying the flow separation maximizes lift and minimize drag.
An automated control system for controlling the flow condition is required for optimized operation of the wind turbine. Such a control system requires measurement of flow conditions on a continuous basis, particularly in severe or turbulent operating environments.